Illustrative Example. Arthur bought some apples and twice as many oranges
for 78 cents. The apples cost 3 cents apiece, and the oranges 5 cents apiece.
How many of each did he buy?
Let x = number of apples,
2x = number of oranges,
3x = cost of apples,
10x = cost of oranges.
3x + 10x = 78
13x = 78
x = 6
2x = 12
Arthur bought 6 apples and 12 oranges.
1. Mary bought some blue ribbon at 7 cents a yard, and three times as much
white ribbon at 5 cents a yard, paying $1.10 for the whole. How many
yards of each kind did she buy?
2. Twice a certain number added to ¯ve times the double of that number
gives for the sum 36. What is the number?
3. Mr. James Cobb walked a certain length of time at the rate of 4 miles an
hour, and then rode four times as long at the rate of 10 miles an hour, to
¯nish a journey of 88 miles. How long did he walk and how long did he
4. A man bought 3 books and 2 lamps for $14. The price of a lamp was twice
that of a book. What was the cost of each?
5. George bought an equal number of apples, oranges, and bananas for $1.08;
each apple cost 2 cents, each orange 4 cents, and each banana 3 cents. How
many of each did he buy?
6. I bought some 2-cent stamps and twice as many 5-cent stamps, paying for
the whole $1.44. How many stamps of each kind did I buy?
7. I bought 2 pounds of co®ee and 1 pound of tea for $1.31; the price of a
pound of tea was equal to that of 2 pounds of co®ee and 3 cents more.
What was the cost of each per pound?
8. A lady bought 2 pounds of crackers and 3 pounds of gingersnaps for $1.11.
If a pound of gingersnaps cost 7 cents more than a pound of crackers, what
was the price of each?